You-Get - Command-line utility to download media contents from the web
CONV. - Convert YouTube video to MP3, GIF or MP4
Softorino YouTube Converter - Download YouTube video & audio. Watch and listen offline
Yout - YouTube to Mp3 Converter
Peggo - Peggo is a best and feature-rich mp3 and mp4 converter that allows you to download audio and video files from YouTube and SoundCloud.
PinDrive - PinDrive Never lose your car again